Update from High Sierra

carole77 wrote:

My iMac is mid 2020. Can I update from High Sierra? If so how?

You may need to clarify your exact model of iMac and the version of Mac OS, as the 2020 iMac was released with Mac OS 10.15.

System Preferences > Software Updates.

It should run and tell you what's available. You can go all the way to the latest OS Monterey 12.3.

Stedman is correct, you likely DO NOT own a 2020 iMac. Please check in About this Mac.